HARRISBURG, Pa. (AP) — Common ground is scarce in the Pennsylvania governor's race, the only statewide election contest in 2014. Republican incumbent Tom Corbett is battling chronically weak polling numbers despite first-term accomplishments that include erasing a multibillion-dollar budget shortfall without major tax increases and signing a transportation-improvement program that has jump-started highway and bridge projects stalled for years. Independent polls show Democratic businessman Tom Wolf, a former state revenue secretary, maintaining a double-digit lead as he presses a liberal agenda in a generally moderate state. The candidates' sharply contrasting views should spur voter interest — and crowd the airwaves with dueling TV attack ads — as Labor Day unofficially launches the campaign for the Nov.